Make particles go to the target object and stick to it
You can use keyed particle system to do that. This is often used to morph an object shape (as particles) to another object shape.



The principle is to set up a particle system (PS) on a first object, then define a second one using the same PS (and eventually a third one, etc.).

For these PS you may set there physics to "No" (as if not, they will fall or move or other).

Now create another object, with a PS (a new one) and having the same amount of particles.

Go to the key section below. And set the (keyed steps you want for it). These steps are based on the previous PS, as they are defined.


The key objects PS definition :


1- Start and end set to 1 (we want them all now)

2- Lifetime depending on what you want

3- Set to faces or volume (you choose)

4- No physics (if physics, that will work too, but theses PS will move)

You can use the same PS for the 3 (or 2 if you want 2) transition objects where particles are transiting above.




The keyed PS


1- Define start, end and lifetime as you need

2- Set physics to 'Key'

3- Add 3 (or 2...) steps in the key using the '+' button

4- For each step assign the wanted key object



You can tune the time (check 'use timing') so that the PS leaves or stays (stuck) more or less a long time from an object to another :